On 26/05/14 18:35, Christoffer Dall wrote:
On Tue, May 13, 2014 at 09:14:04AM -0700, Victor Kamensky wrote:
On arm64 'u32 vgic_eisr[2];' and 'u32 vgic_elrsr[2]' are accessed as one 'unsigned long *' bit fields, which has 64bit size. So we need to swap least significant word with most significant word when code reads those registers from h/w.
Signed-off-by: Victor Kamensky victor.kamensky@linaro.org
arch/arm64/kvm/hyp.S | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S index 0620691..5035b41 100644 --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -415,10 +415,17 @@ CPU_BE( rev w11, w11 ) str w4, [x3, #VGIC_CPU_HCR] str w5, [x3, #VGIC_CPU_VMCR] str w6, [x3, #VGIC_CPU_MISR] +#ifndef CONFIG_CPU_BIG_ENDIAN str w7, [x3, #VGIC_CPU_EISR] str w8, [x3, #(VGIC_CPU_EISR + 4)] str w9, [x3, #VGIC_CPU_ELRSR] str w10, [x3, #(VGIC_CPU_ELRSR + 4)] +#else
- str w7, [x3, #(VGIC_CPU_EISR + 4)]
- str w8, [x3, #VGIC_CPU_EISR]
- str w9, [x3, #(VGIC_CPU_ELRSR + 4)]
- str w10, [x3, #VGIC_CPU_ELRSR]
+#endif str w11, [x3, #VGIC_CPU_APR] /* Clear GICH_HCR */ -- 1.8.1.4
Hmm, the data structure doesn't actually clearly define this as bitmap, but the architecture clearly defines this as two registers. It feels like this critical code is getting over complicated to cater for the fact that we can use a convenient for_each_set_bit() function when we process a maintenance interrupt.
Marc, what are your thoughts on this? Change vgic_process_maintenance and clearly document the array on struct vgic_cpu, or go ahead with this change?
So I've already started abstracting access to ELRSR and EISR in my GICv3 patches, and we could perfectly stick the code swapping code in the accessors, letting the world switch alone.
These changes could easily be lifter from the series, and adapted. This would also make the "bitmap-ification" more obvious.
M.